Lecture 31- Wednesday, March 24 , 2010
Digestion and Absorption of nutrients is completed in the small intestine.
Entire intestinal mucosa is characterized by CRYPTS and VILLI.
a) Complete Digestion
-Crypt Cells lack digestive enzymes but secrete a large volume (3L/d) of alkaline
fluid known as SUCCUS ENTERICUS.
-Villi Cells: do NOT secrete fluid, but ABSORB nutrients, fluids.
-SYNTHESIZE enzymes, retain them in brush border
Yield absorbable products. SLIDE 182 Very large quantities of ions are also reabsorbed from lumen of the GIT.
Protein Resease into Lumen a.a a.a pool
50 g as enzymes
30 g as cells
Most of absorption is reabsorption!
Sites of exchange characterized by: